Magazine fuse-plug



H. H. VINCENT AND J. F. SKINNER.

MAGAZINE FUSE PLUG.

APPLICATION FILED DEC. 6. 1919.

1,383,042, PatentedJlme 28, 1921.

Harry I]. Vinccn Z Jain f ISA inn er UNITED STATES PATENT: OFFICE MAGAZINE FUSE-PLUG.

a Specification of Letters Patent. Patented J 11116 28, 1921.

Application filed December 6, 1919. Serial lie. 343,027.

county of Wayne and State of Michigan,'

have invented a new. and useful Magazine Fuse-Plug, of which the following is a speci- 'fication.

This invention relates to magazine fuse plugs, such as carry a plurality of fuse wires adapted to be successively used.

It is primarily the object of the invention to provide a magazine fuse plug adapted to carry in compact form a considerable number of fuse wires for succesive use, and to provide convenient and simple means for selectively connecting said fuse wires between the terminals of the plug.

A further object of the invention is to provide a magazine fuse plug having a rotative switch member for selectively connecting a series of fuse wires with one of the terminals of the plug, and to subject said switch member to spring pressure to establish and maintain a firm contact of said member with the respective fuse terminals.

In attaining these objects the invention contemplates a fuse plug having a body of insulating material formed with a circular series of tubular chambers for receiving fuses all of which are electrically connected at one and each to one of the terminals of the plug, the other plug terminal having pivotal contact with a spring pressed switch member which is mounted within an insulating cap rotatively secured to the plug, and which carries a projecting contact selectively engageable through rotation of said cap with any of a series of cup-shaped contacts to which the fuses are respectivel connected at their opposite ends. A pre erred embodiment of the invention is hereinafter described, and is illustrated in the accompanying drawing, wherein,

Figure 1 is a View of the improved plug in side elevation.

Fig. 2 is an axial sectional view of the plug drawn to a somewhat larger scale, the plane of section being indicated by line 22 in Fig. 3.

Fig. 3 is a view of the plug with its rota table insulating cap removed.

Fig. 4 is a cross-sectional View taken upon line 4-4 of Fig. 2.

Fig. 5 is an inner I face view of the cap of the plug.

.socket;

Fig. 6 is an exterior view of the capped end of the plug. 7

In these views the reference character 1 designates the core or body of the plug,

which is formed of porcelain or other insulating material, and which is substantially of a cylindrical form. One terminal of the plug is formed by a stem 2 tightly extending axially of the core 1 and having a contact head 3 at the inner end of said core, or the end which is adapted to be inserted in a socket (not shown). At its other end said stem projects slightly beyond the core 1 and is preferably rounded, as is best seen in Fig. 2. A circular series of tubular chambers 4 is formed in the core 1, parallel to and equidistant from the stem 2, and in each of said chambers there is disposed a fuse wire 5. The inner ends of these fuse wires are all electrically connected to the other terminal 6 of the plug, said terminal being in the form of a shell embracing the core 1 and formed with screw-threads to adapt it for engagement in the' usual manner with a The electrical connection between the fuses and terminal is preferablyestablished by a corrugated ring 7, which engages in an'annular groove 8 formed in the inner end portion of the core land opening into the inner ends of the chambers i. The outwardly projecting arcuate portionsof said ring bear firmly against the inner end of the terminal 6, and the inwardly projecting portions register with the chambers 4 and are engaged by the fuses 5, the latter being bent to extend exteriorly ofsaid ring and are preferably soldered thereto. The corrugations are formed after the ring 7 is slipped over the body. A series of cup-shaped terminals 9 for the fuses 5 is set into the outer end of the core 1 in an outwardly offset rela" tion to the chambers .4, the latter being closed by sealing plugs 10. A switch arm 11, forming at one end 'a pivotal engagement and electrical. connection with the stem 2, is adapted to be swung about the axis established by said stem to selectively engage a cup-shaped projection 12, upon its outer end,

with any of the terminal contacts 9 of the fuses. To effect the desired engagement of the arm 11 with the stem 2, it is preferred to merely indent said arm to form a pocket 13 which will snugly receive the projecting rounded end of said stem.

Upon the outer end of the core 1, there is rotatively mounted a cap comprising a body 14 of porcelain or other insulating material and a metal shell 15 embracing said body and extending sufliciently beyond the inner face thereof to embrace the outer end portion of the core 1, said shell being terminally deflected inwardly as is indicated at 16 to tightly engage an annular shoulder 17 upon Said core, whereby the cap is rotatively retained upon the core. The outer end por= tion of the shell 15 isformed with a flange 18 marginally engaging the outer face of the cap 14, from the central portion of the face ofwhich there projects a lug 19 which may be grasped to rotate the cap. The inner face of the cap is formed with a recess 20 proportioned to accommodate the switch arm 11, said recess having a radial relation to the cap and having formed transversely therein a rib 21 adapted to be engaged by the free end of a spring tongue 22 struck out of the center portion of the switch arm, so that the latter will be resiliently pressed against the core 1.

From the foregoing description it will be seen that the cap 1%15 performs four separate functions. That is to say, said cap provides insulating means for turning the switch arm, retains the pivot end of said arm engaged with the stem. maintains the spring tongue 22 under a tension so that the projection 12 on said arm will snap into the cupshaped fuse terminals 9, when registered therewith, and will be maintained in firm contact, and finally said cap covers the sev eral fuse terminals, preventing any arcing between adjacent terminals and avoiding the danger of exposed contacts. Upon blowing of the fuse which is in use, it requires .only a slight turn of the rotative cap to place another one in circuit. Sufiicient indication as to the proper positions of adjustment of the cap to engage the switch arm 11 with the fuse terminals 9 is furnished by the resistance to rotation which results from resting of the projection 12 in any of said terminals.

The described construction is one'that may be quickly assembled and can be manufactured at a comparatively low cost. Soldering of the fuses 5 to the ring '7 is readily accomplished, since the inwardly extended corrugations of the ring form little receptacles for the solder, in conjunction with the walls of the channel 8. Also the utilization of the rotative cap to retain the switch arm in engagement with its pivot stem is a feature that expedites assembly. A desirable compactness results from the arrangement ofthe fuses in a circular series at the center of which the terminal stem 2 is located.

What we claim is:

1. A magazine fuse plug, comprising an insulating core, a pair of terminals for the plug mounted upon said core, a plurality of fuses connected to one of said terminals, a circular series of terminal contacts for said fuses mounted upon an end face of said core, an,insulating cap rotatively engaging said end fuse of the core and formed with a radially extended recess adjacent said face. and a switch arm disposed within said recess, electrically connected to the other ter minal of the plug and rotatively actuable by the plug to selectively engage said terminal contacts, said arm having a struck-out spring tongue stressed by said cap to press the arm against said end face of the core.

2. A magazine fuse plug, comprising an insulating core having a circular series of tubular chambers formed therein, and formed with an annular groove opening into corresponding ends of said chambers, a corresponding series of fuses respectively disposed within said chambers. a shell forming one of the terminals of the plug embracing said core, a corrugated ring engaging in said groove with its outwardly and inwardly deflected portions electrically connected respectively to said shell and to said fuses, terminal contacts for said fuses upon an end face of the core, a stem extending through the core centrally of said series of chambers, and a switch arm pivotally and electrically connected to said stem and rotatable to selectively engage said terminal contacts.

In testimony whereof we sign this specification.

HARRY H. VINCENT. JOHN F. SKINNER. 

